Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754871Ab0DIWn2 (ORCPT ); Fri, 9 Apr 2010 18:43:28 -0400 Received: from terminus.zytor.com ([198.137.202.10]:46124 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753544Ab0DIWnZ (ORCPT ); Fri, 9 Apr 2010 18:43:25 -0400 Message-ID: <4BBFAD49.3000208@zytor.com> Date: Fri, 09 Apr 2010 15:42:17 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100330 Fedora/3.0.4-1.fc12 Thunderbird/3.0.4 MIME-Version: 1.0 To: Alan Cox CC: guenter.roeck@ericsson.com, linux-kernel@vger.kernel.org, Yinghai , Linus Torvalds , Bjorn Helgaas , Thomas Gleixner , Ingo Molnar , "linux-pci@vger.kernel.org" , "x86@kernel.org" , Andy Isaacson , Thomas Renninger Subject: Re: [PATCH] x86: Reserve legacy VGA MMIO area for x86_64 as well as x86_32 References: <20100407210628.28364.96982.stgit@bob.kio> <201004071705.07176.bjorn.helgaas@hp.com> <4BBD13C3.2060404@oracle.com> <201004091004.39857.bjorn.helgaas@hp.com> <4BBF5987.3010100@zytor.com> <4BBF626A.3060800@oracle.com> <4BBF70BC.3080809@zytor.com> <1270839357.1477.758.camel@groeck-laptop> <4BBF89FE.5040909@zytor.com> <1270845108.1477.784.camel@groeck-laptop> <4BBF91C6.9090701@zytor.com> <20100409234245.4081994a@lxorguk.ukuu.org.uk> In-Reply-To: <20100409234245.4081994a@lxorguk.ukuu.org.uk> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1145 Lines: 27 On 04/09/2010 03:42 PM, Alan Cox wrote: >> "Don't use legacy fixed-function addresses for nonstandard purposes." >> >> There, there is your documentation. > > It's probably a good idea to only reserve it if the space is actually > being used. There are a variety of legitimate reasons to use that space > for other things on embedded x86 boards. > > They are only "legacy fixed function" if you have a PCI bus... No they're not. The 0xa0000...0xbffff range has been a legacy video area since the very first PC (although the first PC only used 0xb0000..0xbffff, 0xa0000..0xbffff was declared reserved at that time.) I'm wondering what those legitimate reasons are. This is particularly so since it affects our ability to deal with very early errors, long before we have enumerated anything. At this point we can at least lay down bytes in the video area and hope the user can see them. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/